ANC's spokesman Pule Mabe's former personal assistant has accused him of sexual harassment. Mabe has denied the woman's claims.
The 26-year-old, who asked not to be named, is expected to present her case before the ANC's complaint committee on Wednesday.
The former PA told News24 she was appointed by Mabe himself but described her period in his office as "the most difficult four months".
The woman handed over a 14-page letter, which News24 has seen, detailing the alleged sexual harassment and the first assignment she worked on with Mabe. She claims Mabe forced herself into her bed at two occasions earlier this year.
She said she rejected his advancements and that resulted in her being ill-treated by the national spokesperson ANC as his assistant.
"I could see there was a continuation in how Pule treated me and so on, it led to an unwarranted salary cut." "If you do not say you're going to go down for nothing," she told News24.
The woman says she's aware of claims by Mabe that her complaint is an attempt to get back to him because he raised concerns about her qualifications. But she says he was aware of the fact that she had not completed her degree when he hired her.
"I was hired by Pule and human resources, HR knew, when I arrived at my first day I told him [university]. I never hid that I did not have qualifications and said I'm working on it. "
Toxic working environment
The woman dismissed the idea that she was "used" as a pawn in ANC battles that are playing out at Luthuli House, saying she was an independent woman who had decided "enough was enough".
The former assistant also said Mabe created a difficult working environment, not only for herself, but the entire Department of Information and Publicity at Luthuli House.
News24 also spoke to other workers in the department who described working with Mabe as "hellish" and "toxic", accusing him of having difficulty working with.
However, a number of staffers who are close to Mabe claim he is often undermined by older members who are linked to the previous leader's unit.
Others had previously raised concern over the treatment of his assistant, claiming he often reduced her to tears.
"The working environment is totally toxic, the way he treats us is terrible, we are often shouting and saying we were found at DIP (Department of Information and Publicity), so we obviously serve (Gwede) Mantashe and Zizi (Kodwa) , "said one staffer.
When News24 approached Mabe for comment he initially claimed he knew nothing of the allegations or the woman's appointment with the party's complaint committee. Mabe later confirmed the complaint to News24. He said he would be willing to speak on Wednesday.
In a statement issued on Monday, the ANC has confirmed that a complaint has been lodged at its headquarters last week.
"The panel will hear the case later this week," said Zizi Kodwa, head of the ANC's headquarters, "We have since established a Grievance Panel, as per our personal manual.
The party said it would not comment further until the finalization of these internal processes.